For best privacy AND security, Pixel 8 or 8 Pro with GrapheneOS. Nothing else compares. The Pixel 8 series are also the first that support hardware memory tagging, basically making them immune against 70% of all exploits.
Sure, the Nothing phone is a decent phone but it doesn’t really have anything to offer as far as privacy and security are concerned. On the contrary, I wouldn’t trust Nothing since their iMessage fiasco.